A well-designed test post can avert weeks of wasted work. About 1,500 impressions per variant detect a 2‑point CTR lift (3%→5%) with ~80% power.
Here’s a fast plan with concrete thresholds so you can test once, decide once.
Define Metrics And Sample Size
Choose one primary outcome: CTR for discovery or engaged time for depth (set a 45–60 s floor). Write a falsifiable hypothesis before launch.
Sample sizes: ~1,500 impressions per variant for a 2‑point lift near 4% CTR at 5% alpha and ~80% power; ~6,000 for a 1‑point lift. If volume is low, accept larger effects or longer runs.
Build, Run, Decide
Keep the test post minimal: 300–600 words, one CTA, two headline variants, and constant thumbnail/placement to isolate the headline. Write at grade 7–9; reading time under three minutes.
Run 48–72 hours, cap at seven days. Ship if the 95% interval for lift is above zero and absolute CTR ≥4.5% with engaged time ≥45 s; otherwise iterate on the largest uncertainty.
Conclusion
Set your metric and thresholds, prewrite two headlines, gather the required impressions, then make a single, rules‑based go/no‑go decision to move from testing to production efficiently.
